<template>
  <div>
    <button @click="setNum(-1)">-</button>
    <input type="text" :value="numSon" />
    <button @click="setNum(1)">+</button>
  </div>
</template>
<script>
export default {
  name: 'TestNum',
  props: ['numSon'],
  methods: {
    setNum (step) {
      this.$emit('update:numSon', this.numSon + step)
    }
  }
}
</script>
<style></style>
